Paper pulp baling method and apparatus

ABSTRACT

Method of baling bundles of paper pulp comprising overwrapping the bundle with top and bottom wrapper sheets, and thereafter forming side seams and end flaps about the bale by applying a repulpable adhesive to overlapping areas of the wrapper sheets and exerting a compressive force on these adhesive-carrying areas so as to obtain bonded side seams and end flaps. Apparatus is disclosed for baling bundles of paper pulp, including means for applying a repuplable adhesive to overlapping areas of the wrapper sheets, means for forming side seams and end flaps, and means for exerting a compressive force on the side seams and end flaps.

United States Patent 11 1 Mercer et al.

145 Feb. 19, 1974 PAPER PULP BALING METHOD AND 3,327,452 6/1967 Cranstonet al. 53/218 APPARATUS [76] Inventors: g i i s? 4360 gw PrimaryExaminer-Travis S. McGehee i 'j g q j Attorney, Agent, or FirmEdwa1'd T.McCabe;

Charles E. Bouton; Robert E. Blankenbaker Falrmile Rd., West Vancouver,BC; Frederick A. McDowall, 831 Fairfax Pl., Richmond, BC, all of Canada57 ABSTRACT [22] Filed: May 16, 1972 Method of baling bundles of paperpulp-comprising [21] Appl 253760 overwrapping the bundle with top andbottom wrap- Related US. Application Data per sheets, and thereafterforming side seams and end [63] Continuation-impart of Ser. No. l53,669,June 16, flaps about the bale y pp a repulpable adhesive 1971, which isa -continuation-in-part of Ser. No. to overlapping areas of the wrappersheets and exert- 50,837,June 29, 1970. ing a compressive force on theseadhesive-carrying areas so as to obtain bonded side seams and end flaps.[52] US. Cl 53/32, 53/209, 53/218, Apparatus is disclosed for balingbundles of paper 53/387 pulp, including means for applying a repuplableadhe- [51] Int. Cl B65b 11/02 sive to overlapping areas of the wrappersheets, means [58] Field of, Search 53/32, 209, 218, 383, 387 forforming side seams and end flaps, and means for exerting a compressiveforce on the side seams and [56] References Cited end flaps.

UNITED STATES PATENTS 2,974,461 3/1961 Demler 53/383 X 7 Claims, 8Drawing Figures 13s 2' 7o so 1 90 201, 1 1 ,1 7 M a so 1 o 3 38 4' 4B 1,t/j I ,,/56 3!: 154 I 1/88 36 35 1 64- 3'1: v ,1Il '15 4 \A I VA \j E s4 I I. 8 B4 1 1 v i l l T- l I 4315; i 19 Q o I A G) O .5) 51 l we 7-...a 33 Q 75 we "1 16 12s 5a 54 I me PATENTEDFEBI 91924 SHEET 5 BF 7 1PAPER PULP BALING METHOD AND APPARATUS This invention is acontinuation-in-part of copending application Ser. No. l53,669, filedJune 16, 1971, which in turn was a continuation-in-part of applicationSer. No. 50,837, filed June 29, 1970.

The present invention relates to an improved method for baling bundlesof paper pulp and to improved apparatus suitable to carry out saidmethod of baling. More particularly, the present invention relates to amethod and apparatus for baling bundles of paper pulp overwrapped withtop and bottom wrapper sheets by applying an adhesive to overlappingportions of the wrapper sheets and then applying a compressive force tothese overlapping portions.

Generally, paper pulp is manufactured in sheet form at mills close to asource of supply of timber. Often, however, no paper mills are locatedat the same site as the pulp mills, and therefore the pulp must be baledand then shipped to paper mills or other customers.

At the pulp mill, timber'is processed into a continuous sheet of paperpulp comprising cellulose fibers. The

pulp sheet is passed through a dryer in order to obtain a product ofdesired solids content, usually between about 80% agd 100%. Once thecontinuous pulp sheet is formed and dried, it is auto-matically cut intorectangular sheets, and these sheets are stacked and weighed to obtain aunit weight stack. Top and bottom pulp wrappers are then looselypositioned above and below the stack. Consumer paper mills generallyrequire the pulp stack to be wrapped in these pulp sheets in order toprotect the bale contents from dirt and moisture, the wrapper sheetsbeing eventually repulped by the consumer paper mill. The stack is thentransferred to a hydraulic press which exerts a tremendous downwardpressure on the stack in order to effect a compact bundie. Thiscompression step reduces the height of the stack, correspondinglyreducing the stack volume and resulting in a compact unit which can bemore easily baled.

Baling is accomplished in the paper pulp art by folding the wrappersheets about all six" sides of the pulp bundle, and then tying steelwires or straps transversely and longitudinally about the bundle. Onewire may be secured lengthwise and one wire widthwise, or two or morewires may be tied about each dimension. This operation is performedautomatically by wire tying machines especially adapted for the balingof paper pulp. A description of one of the more popular wire tyingmachines is found in U.S. Pat. No. 3,179,037 to Cranston et al. The wiretying machine automatically encircles a bundle of pulp with a strand ofwire supplied by a continuous spool, .ties the wire securely, and thensnips the wire from the spool. The machine can be adapted to tie severalwires at different increments of length or width along the bale. Beforethe bundle proceeds to the tying machines however, the top and bottomwrappers must be folded about the bundle so as to form side seams andend flaps. Generally, side seams are formed first along the length ofthe bundle by automatically or manually overlapping the top and bottomwrappers. The bundle is then fed into a tying machine to effect atransverse wire tie about the side seams. The partially formed bale isrotated 90, and the end flanges are automatically tucked in to form endflaps. The bale is then conveyed to a second wire tying machine whichwill secure one or more wires longitudinally about the The baling ofpaper pulp with steel wire has created serious problems which plagueboth the pulp industry and the paper industry. For example, at the pulpmills, the use of wire presents a considerable expense. The cost of wireper bale may range from a few cents up to more than 20 cents, dependingon the number of wires placed about each bale. When it is consideredthat a medium to large paper pulp mill may manufacture from 500 to 1,500tons of pulp per day (about 2,000 to 6,000 bales per day), it can beseen that the cost of wire constitutes a major expense. Moreover, thecomplexity of the wire tying machines causes frequent mechanicalproblems which may require shutdown of the whole baling line, thuslowering daily production levels,

When the wire-baled pulp-reaches a paper mill, even greater problems areinvolved. For example, removal of the wire from the bales is difficultand timeconsuming. Also, removal of the wire often causes injury toemployes, such as eye injury, due to the elastic spring of the sharpwire when it is cut from the bale. The most serious problem is thatpieces of the wire sometime get into the paper beaters, scoring therollers and cutting through the felts so .as to cause costly equipmentdamage. Moreover, disposal of the wire once it has been removed from thebale is a problem inasmuch as the wire has essentially no scrap value.

In view of the many serious problems created by the use of wire inbaling paper pulp, those skilled in the art have long sought a bettermethod of baling. However, to the best of our knowledge, no feasiblealternative has yet been developed. One direction of inquiry by thoseskilled in the art has been the use of adhesives to bale paper pulp; butsuch efforts, for various reasons, have not been successful. In U.S.Pat. No. 3,330,409 to Jorgensen, there is disclosed a pulp bale securedby two or more paper pulp bands made endless about the stack of pulpsheets; the bands can be secured at meeting ends by the use of anadhesive such as animal glue. The Jorgensen invention however, does notcontemplate the baling of pulp overwrapped with top and bottom wrappersheets as is the general custom in the art. Moreover, the Jorgensenmethod requires an adhesive set time of up to 10 minutes in order toobtain a suitable bond, whereas in a typical pulp mill baling line, thebale must be bonded within from about l0 to 20 seconds. For thesereasons, the Jorgensen invention does not solve the problems presentedby wire-baling of paper pulp.

in U.S. Pat. No. 2,765,838 to Brown, there is disclosed a method andapparatus for packaging a stack of fibrous mats in kraft paper, using athermosetting adhesive to bond overlapping portions of the paper. TheBrown invention however, is not applicable to the problem of balingpaper pulp in pulp wrapper sheets. Thermosetting adhesives are generallynon-'repulpable,

i.e. not water soluble or dispersible, and thus would not be amenable topulp baling because of the need to repulp the wrapper sheets. Thus theBrown invention does not solve the problems inherent in the baling ofpaper pulp.

It is accordingly a principal object of the present invention to providean improved method and apparatus for baling paper pulp. I

Another object of the present invention is to provide an improved methodand apparatus for baling paper pulp without the use of wire.

It is a further object of the present invention to provide an improvedmethod and apparatus for adhesively bonding top and bottom wrappersheets about the six sides of a bundle of paper pulp.

It is an additional object of the present invention to provide animproved method and apparatus for effecting greater speed and lessexpense in the baling of paper pulp.

It is also an object of the present invention to provide an improvedbaling apparatus which is interchangeable with wire tying units in apaper pulp baling line.

Another object of the present invention is to provide an adhesivelybonded pulp bale wherein the wrapper sheets are suitable for repulping.

Basically, the present invention contemplates a method of baling a stackof paper pulp wherein the stack is overwrapped with top and bottomwrapper sheets. The wrapper sheets are folded about the bundle of pulpsheets so as to obtain overlapping side and end flanges to which arepulpable adhesive is applied. These adhesive-bearing flanges are thensubjected to a high compressive force in order to achieve a rapid,durable bond which retains the wrapper sheets securely about the pulpbundle.

Apparatus for performing this method will comprise, in addition to meansfor folding the side and end flanges of the wrapper sheets, means forapplying adhesive to said flanges, and means for applying a highcompressivee force to the adhesive-bearing flanges.

Further objects and advantages of the present invention will. becomeclear from the following description of the invention taken inconjunction with the drawings, wherein:

FIG. 1 is a flow diagram ofa pulpbaling line incorporating the presentinvention.

' FIG. 2 is a diagram illustrating the folding sequence of a paper pulpbale.

FIG. 3 is a side elevation ofa portion of apulp baling lineincorporating the present invention.

FIG. 4 is a plan view of a'portion of a pulp baling line incorporatingthe present invention.

FIG. 5 is a perspective view of the adhesive press means.

FIG. 6 is a plan view in partial section of one side compression plate.

FIG. 7 is a side elevation view of a portion of the side compressionplate, showing'the spring-load assembly.

FIG. 8 is a schematic drawing of the hydraulic power system.

According to the method of this invention, sheets of paper pulp in theform of a bundle can be securely baled without the use of wire. Themethod is applicable to pulp prepared from both gymnosperms (softwood)such as spruce, hemlock, flr, pine and cedar, and from angiosperms(hardwood) such as aspen, birch, beech, maple, oak and gum. The pulp mayalso be prepared from old paper, rags and other fibrous raw materialsuch as straw, esparato, jute, flax, hemp, corn stalks, bagasse andbamboo. Moreover, the inventive method is applicable to pulp prepared bydifferent processes such as mechanical pulping, semichemical pulping,and chemical pulping including the sulfate process, the sulfite process,the soda process, and the kraft process. Of these processes, the sulfateprocess, and the kraft variation thereof, are probably the mostimportant. The sulfate process is amenable to both softwoods andhardwoods, but is usually used with softwoods because of the long,strong fibers obtained.

After the pulp is formed into a continuous sheet and dried, it isautomatically cut into rectangular sheets which may range from about 27to 36 inches in width and from about 30 to 40 inches in length. Thesheets are stacked and weighed so as to obtain stacks of unit weight,usually about 500 lbs. each. The stack is then compressed to reduce itsvolume and form a compact bundle. Thereafter, top and bottom wrappersheets are loosely positioned above and below the bundle, eitherautomatically or by hand. The wrapper sheets are typically cut from pulpprepared at the mill, but are cut into larger sizes than the normal pulpsheets in order to provide sufficient surface area for the sheets tocompletely overwrap the pulp bundle. It is important that the wrappersheets are positioned in register with the stack. That is, there shouldbe substantially equal projections of the wrapper sheets on both sidesof the stack, and at both ends thereof, so as to insure that there willbe an overlap of the top and bottom wrappers when they are folded. Inthis way, sufficient surface area is provided where the side and endflanges overlap to allow for adhesive bonding of the top wrapper to thebottom wrapper. It should also be noted that it is possible to use twobottom wrappers with one top wrapper, or two top wrappers with onebottom wrapper, or two of each. Usually however, only one top and onebottom wrapper will be employed.

After the wrapper sheets are positioned in register with the bundle, theside seams are formed andbonded, and then the end flaps are formed andbonded. The side flanges may be folded manually or automatically bylifting the projecting sides of the bottom wrapper upward along thelength of the bundle, and forcing the projecting sides of the topwrapper downward along the length of the bundle, and into overlappingrelation with the bottom wrapper. The bottom flanges could be made tooverlap the top flanges, but it is preferable to overlap the bottomflanges with the top flanges.

Prior to overlapping engagement of the top and bottom wrappers along thelength of the bundle, a repulpable adhesive is applied to areas of thewrapper side projections which will overlap. The adhesive may be appliedto one wrapper, or both. When the top wrapper is to overlap the upwardextending flanges of the bottom wrapper, adhesive may be applied to theouter surface of the bottom wrapper side flanges, or to the inner.surface of the top wrapper side flanges, or to both of said areas. Theadhesive may be applied before the side flanges are urged upward anddownward along the length of the bundle, or the adhesive may be appliedto the flanges after they are partially folded upward and downward alongthe bundle but prior to actual overlapping engagement.

Application of the adhesive may be effected by any convenient means,such as spraying, extrusion, brushing, or rolling. The pattern ofadhesive application can be selected as desired, and for example, mayconstitute a continuous thin film of from about 2l0 inches in width, acontinuous bead, or an intermittent pattern. Preferably, the adhesive issprayed to form a thin continuous band of adhesive about 5 inchesinwidth along the outer surface of the upwardly extending bottom wrapperside flanges on each side of the bale.

Once the adhesive has been applied to the side flanges, they may beurged into overlapping contact. The adhesive-bearing side seams are thensubjected to a powerful compressive force which drives the adhesive intothe pulp wrapper sheets. Because of the deep pen- 5 etration of theadhesive into the pulp wrapper sheet, a very strong bond is obtained,and further, the adhesive will exhibit greater moisture resistance. Theamount of pressure required to effect a strong, durable bond is afunction of several parameters, including length of time make possible aquicker, stronger bond, it is preferable to exert a downward compressiveforce on the top of the bale in order that buckling and bale deformationcan be prevented, while still exerting a high compressive force on theside seams. Generally, it has been found that pressures of greater thanabout 10 psig are required to effect a sufficient bond. As has beenindicated, the upper pressure is limited only by bale deformation, andmay be in excess of 350 psig. When no compressive force is exerted ontop of the bale to prevent bale deformation, a preferred pressure rangefor effecting a strong adhesive bond is from about 10 psig to aboutpsig.

However, as already mentioned, the preferred mode of this inventionincludes the simultaneous application of a compressive force on the topof the bale in order 30 to prevent bale buckling and deformation whilethe side seams are being bonded. This anti-buckling pressure may rangeup to 15 psig, and above. A preferred 'ian 'eor antiiiiickling pressureis frOrnEBoutTp sig tB S about 10 psig. It will be obvious of course,that the greater the anti-buckling pressure, the greater the side seambonding pressure may be. When an anti-buckling pressure is applied tothe top of the pulp-bale, the side seam bonding pressure applied willpreferably be from about 25 psig to about 75 psig, and most preferably 4from about 30 psig to about 60 psig.

The compression dwell time may be varied in accordance with the adhesiveemployed and the compressive force applied to the bale. It must be notedhowever that a vertical fold is required. The folding operation isgenerally carried out automatically by first folding the projecting sideflaps sideways across the end of the bundle, and then folding the topand bottom flaps vertically to overlap the transverse fold. Preferably,the transverse fold is made first, then the bottom flap is foldedupwardly, and finally the top flap is folded down over the bottom flap.When the end flaps are to be folded in this manner, adhesive may beapplied to the outwardly facing surface of the bottom flap or to theinwardly facing surface of the top flap, or to both of said surfaces.The adhesive may be applied prior to folding the end flaps, or at anytime during the folding thereof. As with the side seams, application ofadhesive may be any convenient means such as spraying, extruding,brushing, or rolling; and the pattern of application may be selected asdesired, and preferably will be a thin continuous band about 2l0 inchesin width.

After adhesive has been applied to the selected surface areas of the endflaps, the flaps are urged into overlapping engagement, and the bale isthen ready for the compressive bonding step. Similar to bonding of theside seams, a compressive force of greater than about 10 psig is used toobtain a good bond, 'with a range of from about 10 psig to about 30 psigbeing preferable when no downward, anti-buckling compression isutilized. As previously mentioned, the preferred mode of the presentinvention comprises the simultaneous application of a compressive forceto the top of the bale in order to prevent buckling while the end flapsare being bonded. This anti-buckling pressure may range up to 15 psigand higher, and preferably will be from about 2 psig to about 10 psig.When an antibuckling pressure is applied to the top of the bale, the endflap bonding pressure applied will preferably be from about 25 psig toabout 75 psig, and most preferably from about 30 psig to about 60 psig.

The dwell time for the compression is again dictated 0 by the demands ofthe particular baling line, and will the determining factor as to lengthof compression dwell time. is generally the speed of operation of thebaling line. Existing automated baling lines generally require that noone operation on a bale have a dwell time of greater than about 30seconds. Fast baling lines may have a maximum dwell time, for any oneoperation, of less than about 20 seconds. The present method of adhesivebaling is effective to not only meet existing time requirements ofbaling lines, but also, can substantially reduce the time required forbaling. The compression dwell time may be as low as 5 seconds when ahigh tack, fast dry, adhesive is employed in conjunction with a highcompressive force. Preferably however, the time of compression will begreater than about 10 seconds. The upper limit of compression dwell timeis limited only by the speed of the baling line, and for example, couldbe as long as 20 to 30 seconds.

After the side seams have been bonded by application of adhesive andcompressive force, the partially baled bundle is ready for formation andbonding of the 6 normally range between about 10 and 30 seconds. Ofcourse, the compression dwell time can be longer than 30 seconds if thebaling operation so permits. Times as low as 5 seconds may effect asuitable bond where the compressive force is highand the adhesive hasproperties of high tack and fast dry.

The adhesive composition utilized in the present method may be anyrepulpable adhesive which has properties of good tack and fast set time.The adhesive may be a synthetic or natural adhesive derived. from plantor animal sources. A preferred class of adhesive compositions in thecollagen protein colloids containing from about 30-50 percent collagenprotein and from about 50-70 percent water. A second preferred class ofadhesives is thepolyvinyl acetates containing from about 4060 percentpolyvinyl acetate emulsion of 50-60 percent solids, and from about 40-60percent water. A composition containing 50-55 percent polyvinyl acetateemulsion, 40-45 percent water and up to 10 percent of a suitableplasticizer is a particularly good adhesive for baling paper pulp inaccordance with this method. Another suitable class of adhesivecompositions is the repulpable hot melt adhesives having properties offast dry and good tack. High solids content dextrine adhesivescontaining from about 30-50 percent dextrine and 5070 percent water arealso advantageous.

Many other water soluble or water dispersible resins, while notpossessing. the very rapid dry and high tack characteristics of theabove-mentioned adhesives, may be used successfully in slower balinglines. These resins include polyvinyl alcohols, sodium polyaorylate,casein, carrageenin, sodium alginate, methyl cellulose,hydroxyethylcellulose, carboxy-methylcellulose, and mixtures thereof.These resins are generally compatible with the collagen protein colloidswhen in solution, and may be also advantageously combined therewith toprovide suitable adhesive compositions for the purposes of thisinvention. The adhesive should be repulpable inasmuch as the consumerpaper mill will ordinarily want to repulp the wrapper sheets. Thepresence of a non-repulpable adhesive impregnating the wrapper sheetswould render them unsuitable for paper manufacture. By repulpableadhesive is meant an adhesive which is soluble or dispersible in thepaper mill pulp beaters, i.e., water soluble or water dispersible. Oneimportant advantage of using the protein colloid adhesive describedabove is that its presence in the final paper product actually enhancesthe desirable properties of the paper.

It is important to apply the adhesive to the pulp wrapper sheets whilein a flowable state, that is, while having a flowable viscosity, such aswould be suitable for spraying or extrusion. Thus if the adhesive isnormally a solid or a gel at ambient temperatures, as is generally thecase with the collagen protein adhesives, it is necessary to first heatthe adhesive to reduce its viscosity and thus render it flowable.Application of the adhesive while hot has the further advantage ofencouraging rapid migration of the adhesive into the fiber structure ofthe pulp wrapper sheets during the compressive bonding step. Also,application of the adhesive while hot results in rapid evaporation ofsolvent, such as water, which may be present in the adhesive, and thusis conducive to quick drying. The lower temperature of application ofthe adhesive will thus be determined by the point at which it has aflowable viscosity, and will often be room temperature or lower for manyadhesives, such as the polyvinyl acetates described above. On the otherhand, the collagen protein adhesives will generally be applied attemperatures of greater than about 100F. The upper temperature ofapplication will beset by the point of thermal deterioration of theparticular adhesive employed. Collagen protein adhesives should usuallybe applied at less than about l80F., but some hot melt adhesives may beapplied at temperatures ranging up to 400F.

An alternative method of bonding the side seams and end flaps involvesperforation of said side seams and end flaps, as by punching small holestherein, during the compressive bonding thereof. In this manner,penetration of the adhesive into the wrapper sheets is greatly enhanced.Moreover, some of the pulp fibers are interlocked during perforation andcompression, thus further improving the strength of the bond. Theseholes should be relatively small and closely spaced. For example, holesof 1/32 inch diameter spaced at 1/16 inch or A inch centers have beenfound beneficial in achieving good penetration of the adhesive. It isalso possible to perforate the projecting sides and ends of the wrappersheets prior to application of the adhesive.

It should be noted that the excellent results obtained by the inventivemethod described-herein are totally unexpected in view of the verydifficult bonding job required. The bonding job is inherently difficultfor at least two reasons: (I) the small amount of time available toobtain a strong bond, and (2) the bulky nature of the pulp wrappersheets. The pulp wrapper sheets are generally about 6 times thicker thana sheet of paper, and are coarse and unfle xible, thus making the pulpdifficult to fold and bond. Surprisingly, practice of the present methodentails the use of as little as 1 ounce or less of adhesive per 500 lb.bale in many instances.

Apparatus for carrying out the method of the invention is illustrated inthe accompanying drawings. FIG. 1 diagrammatically illustrates a typicalpulp baling line into which the present invention has been incorporated.A continuous feed of pulp is cut into rectangular sheets and stacked inpiles at stacking station 2. The stacks are then conveyed to weighingstation 4 where unit weight stacks, usually about 500 lbs. are obtainedby adding or subtracting pulp sheets. The unit weight stack iscompressed at compression station 6 to obtain a compact bundle of paperpulp. Top and bottom wrapper sheets are loosely associated with thebundle at wrapper positioning station 8, and the bundle is conveyed toside seam forming station 10 where adhesive is applied to projectingsides of the wrapper sheets and these sides are folded into overlappingengagement. The overwrapped bundle is then fed to adhesive press station12 where a high compressive force is exerted on the side seams to obtaina strong adhesive bond. Thereafter, the bundle passes to end flapforming station 14 where the projecting ends of the wrapper sheets arefolded to form end flaps and adhesive is applied thereto. The bundle isconveyed to adhesive press station 16 to provide a high compressiveforce to the end flaps. The completed bale is subsequently transferredto unitizing station 18 where the bales may be stacked in a verticalpile and unitized by securing the pile with a metal strap. The bales arethen ready for shipping and/or storage.

FIG. 2 illustrates a preferred method of folding top and bottom wrappersheets about a paper pulp bundle. In step A, bundle 20 is looselyunderlaid with bottom wrapper 21 and overlaid with top wrapper 22.Bottom wrapper 21 has projecting sides 23 (also referred to asprojecting side flanges) aknges) and projecting ends 24 (also referredto as projecting end flanges). Top wrapper 22 has projecting sides orflanges 25 and projecting ends or flanges 26. In step B, bottom wrapperside flanges 23 have been folded upward against the sides of bale 20,and top wrapper side flanges 25 have been folded downward to overlap thebottom wrapper, thus forming side flaps 27 and side seams 28. In step C,the side flaps 27 have been folded transversely across the end of bundle20, resulting in the formation of bottom flap 29 and top flap 30.Folding of this bale is completed by urging bottom flap 29 upwardagainst the end of bale 20, and subsequently overlapping flap 29 withtop flap 30. Side flaps 27, along with top and bottom flaps 29 and 30will be referred to collectively as the end flaps.

Referring to FIGS. 1-5, pulp bundle 20 is positioned on bottom wrapper21 and is carried in the direction indicated, by endless feed conveyor31 which is driven by motor 32 through belt 33. Bottom wrapper foldingmeans 34, positioned on each side of conveyor 31, includes verticalguides 35 and contoured guides 36. Contoured guides 36 are substantiallyhorizontal at trailing edge 37, but are gradually inclined upwardly to avertical position at leading edge 38. In this manner, guides 36 canengage the outwardly projecting side flanges 23 of bottom wrapper 21 andurge said flanges into a substantially vertical position by the timebundle 20 reaches leading edge 38. A. top wrapper 22 will be positionedover bundle 20 at this time if such wrapper has not previously beenplaced in register therewith.

Adhesive application means, generally 39, includes adhesive tank 40,pump 41 driven by motor 42, and applicator heads 43. Pump 41 drawsadhesive through line 114 and valve 115, and supplies adhesive toapplicator heads 43 through lines 46 and valves 47. Applicator heads 43are stationarily mounted on vertical guides 35 by means of brackets 48,and are equipped with nozzles 50 which are positioned to apply acontinuous adhesive band along the outer surface of bottom side flanges23 as these flanges are conveyed in an upwardly extending position pastnozzles 50. Nozzle design and pressure can be varied to achievedifferent patterns of adhesive application. Pump 41, applicator heads43, and lines 114, 46 may be heated, as by electrical elements (notshown), in order to retain the adhesive in a heated condition until itis applied. Also, adhesive tank 40 may be heated in any convenientmanner, as by steam or electrical heat.

Bale 20 is discharged onto endless machine conveyor 52, driven by motor54 through belt 56, and positions bale 20 at seam forming station 10.Top wrapper folding means, generally 60, are positioned on each side ofconveyor 52 and are operable to fold top wrapper side flanges 25downward to overlap adhesive carrying bottom side flanges 23. Verticalguides 35 extend along each side of conveyor 52 to retain bottom flanges23 in a vertically disposed position. When bale 20 is positionedopposite top wrapper folding means 60, pivotally mounted, hinged foldingplates 62 are actuated to engage side flanges 25 of top wrapper 22.Folding plates 62 are moved in a downward wiping motion by pivotallyattached piston rods 64 actuated by cylinders 66. FIG. 3 illustratesfolding plate 62 in its downward position, in which position it isretained until bale 20 is discharged from seam forming station 10.Cylinders 66 are rigidly mounted on frames 68 which include crossmembers 70 and vertical members 72.

Upon completion of the side flanges folding operation, conveyor 52discharges bale 20 onto endless adhesive press conveyor 74, driven bymotor 73 through belt 75. The adhesive compression means, generally 76,includes frame 78 having vertical members 80 connected by horizontalupper cross member 82. Transverse compression plates 84 are reciprocablyactuated by compression cylinders 86 mounted on vertical frame members80. Anti-buckling plate 88 is reciprocably mounted below frame crossmember 82, and is actuated by cylinder 90 mountedon frame cross member82. When bale 20 is properly positioned at adhesive press station 12,transverse compression plates 84 and antibuckling plate 88 are actuatedto engage the sides and top of bale 20 respectively.,After the desiredcompressive force has been exerted on the bale side seams, compressionplates 84 and anti-buckling plate 88 are retracted.

Bale 20 is discharged by conveyor 74 onto endless turntable conveyor 92which is driven by motor 91 through belt 93. A turntable 94 isassociated with conveyor 92 and is operable to turn a bale restingthereon through a 90 arc. Turntable 94 is positioned in the center ofconveyor 92 between conveyor flights 96, and is raised vertically bylift arm 98 bearing on index plate 100 which is rigidly attached toturntable shaft 102. Turntable 94 is rotated through a 90 arc, while ina raised position, by action of drive chain 104 mounted on shaft 102.Rotation of bale 20 through a 90 arc results in the sides of the balebeing positioned transversely with respect to the direction of advanceof conveyor 92.

Turntable conveyor 92 discharges bale 20 onto endless end foldingconveyor 106 powered by motor 108 through drive belt 110. Conveyor 106positions bale 20 at end flap forming station 14. End flap foldingmeans, generally 114, is positioned in association with conveyor 106 andis operable to fold bale side flaps 27 sideways and end flaps 29 and 30vertically. Apparatus which is particularly suitable for this operationis disclosed in US. Pat. No. 3,327,452 to Cranston et al. Generally, theend flap folding means 1 14 includes bottom flap folders 116, and topand side flap folder 118 which is suspended from carriage 120 onoverhead tracks (not shown). Bottom flap folders 116 are mounted on eachside of conveyor 106' and comprise a frame 122 which carries a pivotallymounted folding paddle 124 thereon. Paddle 124 is normally disposed in ahorizontal direction with respect to conveyor 106, but may be swungthrough a 90 arc to an upright position by means of piston rod 126 whichis pivotally connected to paddle 124. Piston 126 is powered by cylinder128 mounted on frame 122. Actuation of piston 126 swings paddle 124through the 90 arc, thus urging bottom flap 29 into a substantiallyvertical position, as shown in FIG. 3.

The top and side flap folder 118 comprises a top frame 130 carryingguide bar 132. Frame 130 and guide bar 132 are moved vertically byvertical cylinder 134 mounted on carriage 120 and connected to frame 130by piston 136. Vertical hanger bars 138 are downwardly disposed fromslides 140 at each end of guide bar 132. Hanger bars 138 carrytransverse horizontal cross bars 142 which may be drawn together andspread apart by cylinders 144 and piston rods 146. Cylinders 144 andpistons 146 are connected to slides 140 at each end of guide bar 132.

The ends of transverse cross bars 142 carry L-shaped side flap folders148 formed by metal plates 147 and 149. Folders 148 are normallyresiliently held in a 45 position by springs 150. Stops 152 limitrotation of folders 148 in one direction, but when they engage a cornerof bundle 20, they are rotated against the springs such that plates 147are in a position perpendicular to transverse cross bars 142. In thismanner, a sideways fold is effected on side flaps 27, and top and bottomflaps 29 and 30 are formed.

Top folding paddles 154 are pivotally mountedin journaled shafts (notshown) attached on either side of vertically moving frame 130. Toppaddles 154 are normally held in a horizontal position but may beactuated downward through a 90 are into a vertical position by means ofpivotally attached'piston rods 1 56 powered by cylinders 158 mounted onframe 130. In this manner, top flaps 30 can be folded downward tooverlap bottom flaps 29.

Adhesive application means, generally 160, includes adhesive tank 162,pump 164 driven by motor 166, and applicator heads 168. Pump 164 drawsadhesive from tank 162 through line 169 and valve 170, and suppliesadhesive to applicator heads 168 through lines 171 and valves 172.Applicator heads 168 are fixedly mounted by brackets (not shown) on eachside of conveyor 106 adjacent the bottom flap folders 116. The heads 168are equipped with nozzles 174 which are operable to apply a suitableadhesive pattern to the end flaps of bale 20. Pump 164, applicator heads168, and lines 169, 171 may be heated, as by electrical elements (notshown), in order to retain the adhesive in a heated condition untilapplication. Adhesive tank 162 may be heated by any convenient means.

An alternative means of applying adhesive to the end flaps of a baleinvolves mounting applicator heads 168 on a moving carriage (not shown)which is operable to advance the applicator heads 168 forward and backalong a defined path parallel to the direction of ad vance of pulp bales20. The defined path can constitute a track (not shown) extending adistance equivalent to the breadth of one bale. In this mannerapplicator heads 168 can be synchronized to perform a two-passapplication cycle in sequence with the folding of the end flaps. Thus,once folders 148 have effected a side ways fold on flaps 27, applicatorheads 168 will be automatically actuated to travel forward along thedefined path, applying a band of adhesive across the folded end flaps27. It is preferable to have metal plates 147 cut out in a horseshoedesign so as to enable application of the adhesive across the entirewidth of bale 20. Thereafter, bottom paddles 124 will be automated tofold bottom flaps 29 upward against the adhesivebearing, transversefolded side flaps 27. Subsequently,.

applicator heads 168 will be actuated to travel backwards along thedefined path returning to their initial position, while applying a bandof adhesive across upwardly folded bottom flaps 29. Finally, top foldingpaddles 154 will be actuated to fold top flaps 30 downward intooverlapping engagement with adhesive-bearing bottom flaps 29.

Bale 20 is subsequently discharged onto bale press conveyor 176, drivenby motor 175 through belt 177, which positions bale 20 at end flapcompression station 16. The adhesive compression means, generally 76,has the same construction and operation as heretofore defined inconjunction with the description of the side seam adhesive press. When abale is properly positioned at press station 16, transverse compressionplates 84 and anti-buckling plate 88 are actuated to engage the ends andtop of the 'bale respectively. Plates 84 and 88 are then retracted andthe completed bale is discharged.

Referring to FIGS. -8, and describing adhesive compression means 76 withgreater particularity, it will be seen that adhesive press frame 78 maybe mounted on swivel wheels 180. One of the advantages of the presentinvention is that compression means 76 may be easily rolled into and outof a typical pulp baling line. The baling line need not be rebuilt orotherwise rearranged when employing the present adhesive press system.Thus pulp bundles may be baled with either adhesive or wire by quicklyinterchanging apparatus.

Compression plates 84 are actuated by piston rods 184 extending throughframe members 80 into threaded sleeves 185 affixed to side mountingplates 188. Likewise, anti-buckling plate 88 is actuated by piston rod190 extending through upper frame member 82 into threaded sleeve 191affixed to top mounting plate 194, Hard rubber interfaces 186 may beprovided between steel hinged platens 189 and side compression plates84. Also, hard rubber interface 196 is provided between top mountingplate 194 and anti-buckling plate 88. Rubber interfaces 186 and 196allow side compression plates 84 and anti-buckling plate 88 to flexslightly when these plates engage the bale. In this manner, the platesare able to flex sufficiently to equally distribute pressure across apulp bale that may be improperly aligned when it enters the adhesivepress means 76.

Hydraulic cylinders 86 are securely mounted on frame vertical members80, and hydraulic cylinder is mounted on frame upper cross member 82.One end of each of stabilizer rods 206 is rigidly secured to mountingplates 188, and the other ends are reciprocably journalled throughvertical frame members 80. Likewise, one end of stabilizer rod 208 isrigidly attached to top mounting plate 194, with the free end extendingthrough frame upper cross member 82 so that rod 208 can reciprocate withplate 88. Stabilizer rods 206 and 208 prevent side compression plates 84and anti-buckling plate 88 from tilting or rotating during reciprocationof these plates into and out of contact with the pulp bale.

A bottom support plate 230 is fixedly mounted between vertical framemembers 80, and is in the same horizontal plane as feed and take-awayconveyors (not shown) servicing the press 76. Support plate 230 hascurved edges 232 located at both the downstream and upstream sides ofthe adhesive press 76 to facilitate entrance and exit of the bale. Thedimensions of support plate 230 should be such that when a bale isproperly positioned in press 76, the trailing end of the bale will beresting on a temporarily stopped advance conveyor at the upstream end ofpress 76 while the leading end of the bale will be resting on atemporarily stopped take-away conveyor at the downstream end of press76. The center of the bale will then rest on support plate 230 so thatthe conveyors will not be repeatedly subjected to the full downwardforce generated by the antibuckling plate 88. It should be understoodhowever, that bottom support plate 230 is not necessary for operation ofthe adhesive press 76. Rather, press 76 can be provided with its ownendless conveyor 74 and 176.

Referring in particular to FIG. 6, it will be seen that one of the sidecompression plates can be mounted on the press frame in such a mannerthat it may be rotated in an approximately 90? arc to facilitate movingthe adhesive press 76 into and out of a baling line. Hinge bolt 224 isinserted through steel bosses welded to hinged platen 189 so that sidemounting plate 188 is connected to hinged platen 189, and thus to sidecompression plate 84, by means of a hinge arrangement. Hinged platen 189is securely affixed to compression plate 84 by means'of bolt 183threaded through platen 189 and hard rubber interface 186. Bolt 183 issunk through a clearance hole in mounting plate 188, thus enabling bolt183 to rotate with compression plate 84. In operation then, when it isdesired to place adhesive press 76 in a baling line, compression plate84, along with rubber interface 186, steel platen 189 and bolt 183 canbe rotated in a 90 are about hinge and bolt 224. To prevent rotation ofthe compression plate 84 during normal usage, lock bolt 226 is threadedthrough tapped locking lug 228,, which in turn is welded to steelreinforcing platen 189.

Referring in particular to FIG. 7, it can be seen that the sidecompression plates 84 may be spring-loaded in order to obtain neat,attractive creases in the wrapper sheet about the whole upper peripheryof the bale. When the antibuckling plate 88 is actuated downward towardthe pulp bale, the sides of plate 88 will contact transverse lip 212 ofthe springload assembly, generally 210., forcing rod 216 and stainlesssteel sliding plate 217 downward. Bracket 214 and abutment 218 arestationarily mounted on side compression plate 84 such that rod 216 canreciprocate therethrough. Collar 220 is rigidly attached to rod 216 sothat downward motion of rod 216 causes collar 220 to compress metalspring 222 against abutment 218.

Sliding plates 217 are made of about ,41 inch stainless steel sheet andhave length dimensions approximately those of the side compressionplates 84, and are vertically disposed in the same plane as compressionplates 84 on opposite sides of the path of travel of the pulp bundle.The sliding plates 217 fit flush against the compression plates 84, andmay extend downward along the face of plates 84 the full depth of thecompression plates, or alternatively may-extend downward along the faceof plates 84 only a few inches from the top thereof. Pressure applied tocompression plates 84 is transmitted through the thin, steel slidingplates 217 to the pulp bundle 20. I

When transverse lip 212 and plate 217 contact bale 20, they cooperate toform a sharp crease along the edge thereof. When the bonding operationis completed and the anti-buckling plate begins to retract, compressedspring 222 will force the spring-load assembly 210 back into normalposition so that the bale is free to move on the next operating station.The leading face of spring-loaded sliding plates 217 have foam rubberlinings 182 with Teflon coated surfaces 181 in order to prevent tearingof the pulp wrappers during compression of the bale. Also, slidingplates 217, compression plates 84, and anti-buckling plate 88 havecurved side edges 83, 85 and 87 respectively, angled away from the baleto prevent tearing of the bale wrapper during compression.

Referring in particular to F 16. 8, the hydraulic power system includeselectric pump motor 234, mounted on hydraulic fluid reservoir 236. Motor234 drives twopart gear pump 238 which in turn supplies hydraulic fluidthrough unloading valves 239 and 240, and then through hydraulic line241 to four-way directional solenoid valve 242. Directional valve.242regulates flow of fluid to side press cylinders ,86 through lines 244,246, and to anti-buckling cylinder 90 through line 248. Fluid returns todirectional valve 242 from hydraulic cylinders 86, 90 through lines 250,252, 254 and then through filter 256 into reservoir 236.

Pump 238 A is a large volume, low pressure pump, whereas pump 238 B is asmall volume, high pressure pump. Initially during a compression cycle,both pumps 238 A, B feed the hydraulic cylinders until a nomial pressureis reached and compression plates 84, 88 are in contact with the bale.Then low pressure unloading valve 240 will recycle hydraulic fluid backto the tank 236 through line 235 and filter 256. High pressure valve 239will continue to direct hydraulic fluid to the cylinders until thedesired final pressure is obtained. If pressure builds up past thisdesired final pressure, valve 239 will recycle fluid back to reservoir236 through line Since anti-buckling plate-'88 is to apply a lowercompressive force than transverse compression plates 84, pressurereducing valve 260 is positioned in line 248 between directional valve242 and hydraulic cylinder 90 so as to reduce the hydraulic pressure offluid directed to the anti-buckling unit. Sequencing valve 262 is placedin hydraulic line 244 between directional valve 242 and compressioncylinders 86, and is preset at a substantially higher pressure thanreducing valve 260. Therefore, reducing valve 260 will open first,passing fluid to cylinder 90 so as to actuate antibuckling plate 88before side compression plates 84 are actuated. in this manner,anti-buckling plate 88 will contact the pulp bale before sliding plates217 make contact, and will maintain a constant downward pressure on thetop of the bale during application of compressive bonding force by thesliding plates 217 and side plates 84. Double lock valve 261 positionedacross hydraulic lines 248 and 254 is operable to lock antibucklingplate 88 in both retracted and extended positions when control valve 242is in a neutral position.

Although the adhesive press means 76 has been shown and described asoperated by a hydraulic fluid system, it should be understood that acompressed air system could also be employed. A hydraulic system hasbeen described because such a system is more versatile within ranges ofhigh compressive force.

It will of course be understood that the amount of compressive forceexerted over the side seams and end flaps of a bale during the adhesivecompression step will be a function of the hydraulic or pneumaticpressure directed to the adhesive compression cylinders 86, the diameterof the piston bore, and the surface area in contact with the bale ofcompression plates 84 and sliding plates 217. Excellent results havebeen obtained by utilizing a 4 inch diameterpiston bore (cross sectionalarea 12.56 sq. in.), and using sliding plates 217 and compression plates84 having the same dimensions of 30 inches by 14 inches (contact surfacearea of sliding plate 420 sq. in.). With pistons and plates of thatsize, a preferred range of hydraulic pressure will be from about 1,000lbs. to about 2,000 lbs., which works out to an actual pressure of about30 to 60 psig across each of the side seams and end flaps of the bale.

Likewise, anti-buckling piston bore may have a 4 inch diameter.Anti-buckling plate 88 preferably has length and width dimensionsgreater than the top dimensions of the bale; thus for a 30 by 33 inchbale, plate 88 could'have dimensions of 31 by 35 inches (surface area1,085 sq. in.). Therefore a hydraulic pressure of 500 lbs. applied bythe piston to plate 88 would generate an actual pressure of about 6 psigacross the top of bale 20.

It should be understood that the compressive forces set forth indescribing this invention necessarily must reflect an average pressure.Thus when it is stated that a compressive force of 60 psig is appliedacross the side seams or end flaps of a bale, this does not mean thatexactly 60 psig is applied uniformly across each inch of the bale incontactwith the sliding plates and compression plates. Rather, thepressure will generally be somewhat reduced at points along the balefarthest from the center. Thus there will generally be a somewhat higherpressure applied at the center of the bales than at the outer portionsthereof. 7

The side flange folding apparatus, end flap folding apparatus,turntable, and adhesive applicator units are preferably operated by acompressed air'system. The conveyor system may be operated by electricmotors or pneumatic motors as desired. The various pneumatic andhydraulic cylinders are controlled by relay valves which may be actuatedeither by solenoids in an electric control system or by pneumatic relayvalves in a pneumatic control system. In an electrical control system,which is preferred, the various operations and sequences are generallyinitiated by limit switches actuated by the pulp bale or by moving partsof the apparatus. For example, limit switches 264, 266 and 268 aremounted on adhesive press frame 78 to insure retraction of allcompression plates before discharge of the bale. The total time of thecompression cycle is controlled by a manually variable timing device(not shown).

The operating and control systems have not been illustrated fully asthese are well understood in the art, and the program of operations mustserve the varying requirements of each particular pulp baling line.These requirements vary to the extent that no particular control systemcan be considered as standard. A control system designed for one pulpmill installation would probably not be suitable for another.

Obviously, many modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof, and therefore only such limitations should be imposed asare indicated in the appended claims.

We claim:

1. A method for baling bundles of paper pulp comprising: positioning topand bottom wrapper sheets, having projecting side and end flanges, inregister with the top and bottom of a pulp bundle; applying a repulpableadhesive to a portion of the projecting side flanges; forming side seambonds by folding the side flanges into overlapping relationship, thenfirst applying an anti-buckling force of greater than about 2 psig tothe top of the pulp bundle, and immediately thereafter applying acompressive force of greater than about 10 psig to said overlappingflanges for a time greater than about 5 seconds while maintaining saidantibuckling force; forming end flaps in the wrapper sheets by foldingsaid projecting end flanges; applying said adhesive to a portion of saidend flaps; and forming end flap bonds by first applying an anti-bucklingforce of greater than about 2 psig to the top of said pulp bundle, andimmediately thereafter applying a compressive force of greater thanabout psig to said end flaps for a time greater than about 5 secondswhile maintaining said anti-buckling force.

2. The method of claim 1 wherein an anti-buckling force of from about 2psig to about psig is applied to the top of the bale while a compressiveforce of from about 25 psig to about psig is applied over the side seamsand end flaps for from about 10 to 30 seconds.

3. The method of claim 2 wherein the adhesive is applied in a spraypattern and is selected from the group consisting of collagen proteinadhesives, polyvinyl acetate adhesives, and repulpable hot meltadhesives.

4. The method of claim 3 wherein an anti-buckling force of from about 2psig to about l0 psig is applied to the top of the bale while acompressive force of from about 30 psig to about 60 psig is applied overthe side seams and end flaps for from about 10 to 20 seconds.

5. The method of claim 4 wherein the adhesive is a polyvinyl acetateadhesive comprising from about 40-60 percent water and from about 40-60percent polyvinyl acetate emulsion having 50-60 percent solids.

6. In a system for adhesively bonding bundles of paper pulp within topand bottom wrapper sheets having projecting side and end flanges,wherein the bundles move along a defined path, undergoing sequentialoperations, said system including (a) means for applying adhesive to aportion of the projecting side and end flanges of said wrapper sheets;and (b) an adhesive press means including a frame, a pair of sidecompression plates vertically disposed on opposite sides of the path oftravel of said pulp bundle and reciprocably mounted on said frame .forhorizontal movement towards and away from said pulp bundle and anantibuckling compression plate positioned above said path of travel andin the same plane as the top of said bundle and reciprocably mounted onsaid frame for vertical movement into and out of engagement with saidpulp bundle; the improvement which comprises: providing each of saidside compression plates with a spring-load assembly for effecting neatcreases in the wrapper sheet about the upper periphery of the bundle,said springload assembly comprising a rigid sliding plate extendingsubstantially flush along the leading face of said compression plate anddownward across at least a portion of the depth of said compressionplate such that pressure applied to the compression plate may betransmitted through the sliding plate to the bundle; and a transverselip rigidly affixed to the top of. said sliding plate and perpendicularthereto, both said sliding plate and said lip being mounted on thecompression plate by means of a metal spring, whereby actuation of theantibuckling plate forces said lip and sliding plate downward againstthe resistance of the spring until said transverse lip engages the topof the bundle.

7. The system of claim 6 wherein the leading face of the sliding plateis lined with foam rubber.

Patent NQ- 19;}93 UNlTED STATES PATENT OFFICE .ifill'il I H .A'IIC (")F(10R R WZll 0N Dated February 19,. 19711,

Inventofls) Cecil S. Mercer, Archibald D. Beveridge and Frederick A.McDowell It is certified that error appears in the above-identifiedpatent and thet said Letters Patent are hereby corrected as shown below:

The patent should show an its face that it is assigned to swift 80Company of Chicago, Illinois.

Signed and sealed this 17th day of September 1974.

(SEAL) Attest: COY M. GIBSON JR. c. MARSHALL DANN Afitesting OfficerCommissioner of Patents

1. A method for baling bundles of paper pulp comprising: positioning topand bottom wrapper sheets, having projecting side and end flanges, inregister with the top and bottom of a pulp bundle; applying a repulpableadhesive to a portion of the projecting side flanges; forming side seambonds by folding the side flanges into overlapping relationship, thenfirst applying an anti-buckling force of greater than about 2 psig tothe top of the pulp bundle, and immediately thereafter applying acompressive force of greater than about 10 psig to said overlappingflanges for a time greater than about 5 seconds while maintaining saidanti-buckling force; forming end flaps in the wrapper sheets by foldingsaid projecting end flanges; applying said adhesive to a portion of saidend flaps; and forming end flap bonds by first applying an anti-bucklingforce of greater than about 2 psig to the top of said pulp bundle, andimmediately thereafter applying a compressive force of greater thanabout 10 psig to said end flaps for a time greater than about 5 secondswhile maintaining said anti-buckling force.
 2. The method of claim 1wherein an anti-buckling force of from about 2 psig to about 15 psig isapplied to the top of the bale while a compressive force of from about25 psig to about 75 psig is applied over the side seams and end flapsfor from about 10 to 30 seconds.
 3. The method of claim 2 wherein theadhesive is applied in a spray pattern and is selected from the groupconsisting of collagen protein adhesives, polyvinyl acetate adhesives,and repulpable hot melt adhesives.
 4. The method of claim 3 wherein ananti-buckling force of from about 2 psig to about 10 psig is applied tothe top of the bale while a compressive force of from about 30 psig toabout 60 psig is applied over the side seams and end flaps for fromabout 10 to 20 seconds.
 5. The method of claim 4 wherein the adhesive isa polyvinyl acetate adhesive comprising from about 40-60 percent waterand from about 40-60 percent polyvinyl acetate emulsion having 50-60percent solids.
 6. In a system for adhesively bonding bundles of paperpulp within top and bottom wrapper sheets having projecting side and endflanges, wherein the bundles move along a defined path, undergoingsequential operations, said system including (a) means for applyingadhesive to a portion of the projecting side and end flanges of saidwrapper sheets; and (b) an adhesive press means including a frame, apair of side compression plates vertically disposed on opposite sides ofthe path of travel of said pulp bundle and reciprocably mounted on saidframe for horizontal movement towards and away from said pulp bundle andan anti-buckling compression plate positioned above said path of traveland in the same plane as the top of said bundle and reciprocably mountedon said frame for vertical movement into and out of engagement with saidpulp bundle; the improvement which comprises: providing each of saidside compression plates with a spring-load assembly for effecting neatcreases in the wrapper sheet about the upper periphery of the bundle,said spring-load assembly comprising a rigid sliding plate extendingsubstantially flush along the leading face of said compression plate anddownward across at least a portion of the depth of said compressionplate such that pressure applied to the compression plate may betransmitted through the sliding plate to the bundle; and a transverselip rigidly affixed to the top of said sliding plate and perpendicularthereto, both said sliding plate and said lip being mounted on thecompression plate by means of a metal spring, whereby actuation of theanti-buckling plate forces said lip and sliding plate downward againstthe resistance of the spring until said transverse lip engages the topof the bundle.
 7. The system of claim 6 wherein the leading face of thesliding plate is lined with foam rubber.